def solution(s, n):
import string
lower = string.ascii_lowercase
upper = string.ascii_uppercase
answer = ''
for i in range(len(s)):
t = s[i]
if t in lower:
answer += lower[(lower.find(t) + n) % 26]
elif t in upper:
answer += upper[(upper.find(t) + n) % 26]
else:
answer += t
return answer